# add the library that runs
add_library(MathFunctions MathFunctions.cxx)

# state that anybody linking to us needs to include the current source dir
# to find MathFunctions.h, while we don't.
target_include_directories(MathFunctions
        INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
        )

# should we use our own math functions
option(USE_MYMATH "Use tutorial provided math implementation" ON)
if(USE_MYMATH)

  target_compile_definitions(MathFunctions PRIVATE "USE_MYMATH")

  # first we add the executable that generates the table
  add_executable(MakeTable MakeTable.cxx)

  # add the command to generate the source code
  add_custom_command(
          OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/Table.h
          COMMAND MakeTable ${CMAKE_CURRENT_BINARY_DIR}/Table.h
          DEPENDS MakeTable
  )

  # library that just does sqrt
  add_library(SqrtLibrary STATIC
          mysqrt.cxx
          ${CMAKE_CURRENT_BINARY_DIR}/Table.h
          )

  # state that we depend on our binary dir to find Table.h
  target_include_directories(SqrtLibrary PRIVATE
          ${CMAKE_CURRENT_BINARY_DIR}
          )

  # state that SqrtLibrary need PIC when the default is shared libraries
  set_target_properties(SqrtLibrary PROPERTIES
          POSITION_INDEPENDENT_CODE ${BUILD_SHARED_LIBS}
          )

  target_link_libraries(MathFunctions PRIVATE SqrtLibrary)
endif()

# define the symbol stating we are using the declspec(dllexport) when
# building on windows
target_compile_definitions(MathFunctions PRIVATE "EXPORTING_MYMATH")

# install rules
set(installable_libs MathFunctions)
if(TARGET SqrtLibrary)
  list(APPEND installable_libs SqrtLibrary)
endif()
install(TARGETS ${installable_libs} DESTINATION lib)
install(FILES MathFunctions.h DESTINATION include)